Computer communications using acoustic signals

ABSTRACT

A method of communicating with an electronic device. The method includes providing an electronic device having an audible sound receiving and generating sub-system including a microphone, transmitting from a source at least one acoustic signal encoded with information, receiving said at least one acoustic signal by said microphone and determining a spatial position, distance or movement of the microphone relative to the source, responsive to the received at least one signal.

RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 09/806,618 filed on Oct. 9, 2001, which is a national phase ofPCT/IL99/00521 filed Oct. 1, 1999, which claims the benefit of U.S.provisional application 60/115,231, filed Jan. 8, 1999 (attorney docket100/00798), 60/122,687, filed Mar. 3, 1999 (attorney docket 100/00809),60/143,220, filed Jul. 9, 1999 (attorney docket 100/01200), 60/145,342,filed Jul. 23, 1999 (attorney docket 100/01124) and 60/153,858, titled“Card for Interaction with a Computer”, filed Sep. 14, 1999.PCT/IL99/00521 is also a continuation-in-part of PCT applicationsPCT/IL99/00470, filed Aug. 27, 1999 and PCT application PCT/IL99/00506,filed Sep. 16, 1999. The disclosures of all of these applications areincorporated herein by reference.

FIELD OF INVENTION

The present invention relates generally to method of interaction with acomputer and especially to methods that use acoustic signals for suchcommunications.

BACKGROUND OF THE INVENTION

Computer network components that communicate using RF radiation, wiresor IR radiation are well known. In addition, some home appliances arecontrolled using an ultrasonic remote control. Other types of dedicatedultrasonic acoustic links are also known.

However, such dedicated communication mechanisms require that thecomputer network components have installed thereon specializedcommunication hardware. Installing such hardware on an existing computermay be expensive and/or problematic. Further, some electronic and/orcomputer embedded devices, for example cellular telephones may be“sealed” products, to which it is impossible to add internal components.

PCT publications WO96/10880, WO94/17498, WO93/21720 and WO93/11619, thedisclosures of which are incorporated herein by reference, describe anelectronic device which transmits coded information to a microphone of atelephone using a DTMF-like encoding scheme. A WWW page addressed“http://www.encotone.com/html/tech_def.html”, available on Feb. 1, 1999and predated, suggests using such a device to transmit audible DTMF-liketones to a personal computer using the computer's sound card.

Two way communications using audible DTMF-like tones, between a smartcard and a telephone communication system is described in U.S. Pat. No.5,583,933, the disclosure of which is incorporated herein by reference.

SUMMARY OF THE INVENTION

One object of some preferred embodiments of the invention is to simplifyinteraction between electronic devices by removing a common requirementof installing dedicated communication hardware on the devices. Somesuitable electronic devices include: computers (e.g., desktop andlaptop), televisions, watches, PDAs (Personal Digital Assistant),organizers, electronic toys, electronic games, voice-responsiveappliances, wireless communication devices, answering machines anddesktop telephones. As used herein the term “electronic device” is usedto encompass a broad range of electronics-including devices. In some ofthe embodiments described below, a particular type of electronic deviceis singled out, for example a computer or a toy, as some of thebelow-described embodiments are more useful for some types of electronicdevices, than for other types of electronic devices. However, suchexamples are not meant to limit the scope of the invention.

An object of some preferred embodiments of the invention is allowingelectronic devices to communicate using an input and/or output channel,preferably an acoustic channel, but possibly a visual channel, which wasdesigned for communication with human users and not for communicationwith electronic devices. In other cases, the communication channel isnot originally intended for communication with outside components atall, for example, a diskette drive.

An object of some preferred embodiments of the invention is to allow asmart card to be read by and written to using standard computer hardwarewithout requiring an installation of specialized hardware. This isespecially useful for electronic wallets and Internet commerce, wherethe cost of installing dedicated hardware may prevent wide acceptance ofthese commercial methods. Additionally, using a smart card can providemethods of solving the security and accountability issues entailed inelectronic commerce.

An aspect of some preferred embodiments of the invention relates tocommunicating with a computer using a sound card installed on thecomputer. In some computer configurations the installation is permanent,for example as part of the motherboard chip-set. In a preferredembodiment of the invention, a device, preferably a smart card,transmits information to the sound card's microphone and receivesinformation from the computer using the sound card's (or the computer's)loudspeaker. Preferably, the transmission uses non-audible acousticfrequencies, for example ultrasonic or infrasonic frequencies. It shouldbe noted that standard music cards are designed for music generation,and specifically for audible audio frequencies, such as between 20 Hzand 16 kHz, however, they have a limited reception and transmissionability in the near-ultrasonic (e.g., between 16 kHz and 50 kHz) andinfrasonic (e.g., 0.01 Hz to 20 or 40 Hz) frequency ranges. Thedefinition of audible frequencies will usually depend on the user andthis, may, in some embodiments, impact on the selection of frequenciesfor use. Possibly, a personalization software for selecting thefrequencies will be provided. Also, in some applications, the higher endof the audible range may be used, for example 14 kHz-16 kHz, as thesensitivity to these frequencies is quite low, even in those individualsthat can detect them.

Ultrasonic communication has several advantages over audiocommunication:

(a) smaller transducers can be used;

(b) transmission is more efficient;

(c) lower noise levels are typical;

(d) resonant frequencies that have wavelengths on the order of a size ofa credit card can be used; and

(e) higher data rates can be achieved.

In a preferred embodiment of the invention, the ultrasonic frequenciesused are low ultrasonic frequencies or high audible frequencies, forexample between 15 kHz and 24 kHz, more preferably between 17 kHz and 20kHz and, in some preferred embodiments, between 21 and 23 kHz. Often,these frequencies can be transmitted and/or received using standardaudio components. For this reason, lower frequencies may be preferredover higher frequencies, even though the lower frequencies typicallyafford a lower data rate and are more easily disrupted. These particularfrequencies are suggested because they match industry standards forsampling in audio cards (e.g., “SoundBlaster”). If other samplingfrequencies are available, the preferred frequency may adjustedaccordingly. Preferably, a minimum frequency used is selected so that itis inaudible to a human. In some cases, the frequency selection maydepend on the age of the human.

A benefit of ultrasound over RF transmission is that the range of theultrasonic transmission can easily be controlled by varying itsamplitude. Typically, ultrasonic transmissions do not pass throughwalls, potentially providing increased security by limitingeavesdropping and inference from outside the room. In addition,ultrasonic transmissions do not usually interfere with the operation ofelectronic equipment, even when used at a high power setting. Thus,ultrasonic communication is better suited for people with pacemakers andfor hospital settings. Another advantage of acoustic transmission is areduced perceived and actual health danger to the user.

An aspect of some preferred embodiments of the invention relates tocommunication between electronic devices using acoustics. Alternativelyor additionally to electronic devices communicating using RF; varyingmagnetic fields; IR; and visible light, electronic devices maycommunicate using acoustics, in accordance with preferred embodiments ofthe invention. In some cases, one communication direction is acousticand the other is non-acoustic, for example RF or IR, for example whencommunicating with a set-top box in accordance with a preferredembodiment of the invention (one way acoustic from the TV and the otherway IR, in the same manner as with an IR remote control). In a preferredembodiment of the invention, the acoustic waves used for communicationsare incorporated in sounds used for regular operation of the devicewhich generates the sounds, for example by modulating beeps.Alternatively or additionally, the sounds are inaudible, for examplebeing ultrasonic, infrasonic, of a low amplitude and/or causing onlysmall changes in amplitude and/or frequency of an existing soundedsignal.

It is noted that many electronic devices include a microphone and/or aspeaker. In a preferred embodiment of the invention, the microphoneand/or speaker are used to communicate with the device. In one example,an acoustic smart card (or an “electronic wallet” card) communicateswith such a device using sound and/or ultrasound. Such a smart card maytransmit information stored thereon. Possibly, the information isencrypted, for example, using RSA or DSA encryption.

In a preferred embodiment of the invention, a smart card may be “swiped”at many existing computers and electronic devices, possibly requiring asimple software installation, but no hardware installation (assumingsome acoustic hardware exists). Such simple swiping should easeacceptance of the card by Internet browsing home shoppers. In somecases, the swiping software may be downloaded as a Java Applet or as ascript in a different network programming language.

In some embodiments other types of electronic devices communicate. Forexample, a cellular telephone and a PDA, each of which includes amicrophone and a speaker, can communicate. Another example isprogramming a cellular telephone with names and numbers stored in a PDAor for the cellular telephone to interrogate the PDA regarding aparticular telephone number. Alternatively or additionally, a networkmay be formed of a plurality of such devices, possibly, with one deviceforwarding messages from a first device to a second device.Alternatively or additionally, peripherals may be connected to acomputer using an acoustic connection, without requiring wiring orspecial hardware. In some embodiments, a single acoustic transducer(microphone or speaker) may be controllable to act as both a receiverand a transmitter, by suitably programming the electronic device.

Many computers are sold with a Sound-Blaster Compatible sound subsystem,stereo speakers and a microphone. Some computers are provided with othertypes of sound systems, which types also support the application ofpreferred embodiments of the invention, possibly with a variation infrequencies to account for different circuit or samplingcharacteristics. Typically, this sound system is designed for generatingmusic and other audible sounds. In addition, many computers include aninternal speaker and a modem speaker. Some computers use USB speakersthat are connected directly to the USB (Universal Serial Bus).

It should be appreciated that in some embodiments of the invention thesound communication is directed at the device for its use, controland/or processing and is not meant for mere passing through the device.For example, a telephone may interpret computer-information encodingsignals, rather than transmitting them on through the telephone network,as is done in the art. In a preferred embodiment of the invention, awireless telephone is realized using ultrasonic communication between abase station and the hand set. In a preferred embodiment of theinvention, the base station is embodied in a computer, whichcommunicates with the telephone. Possibly, the wireless communicationuses the same loudspeaker and/or microphone as used for communicationwith a person using the telephone and/or the computer. Additionally oralternatively, the handset is used for Internet telephony, via thecomputer without a cradle or other special connection between thecomputer and the telephone.

An aspect of some preferred embodiments of the invention relates tointerfacing a device (possibly a toy) with a computer system withoutinstalling special or dedicated hardware on the computer. Suchinterfacing may use EM-coupling into cables attached to the computer,detection of RF signals from a computer or direct input into a mouse ora keyboard. In one preferred embodiment, the loudspeakers, alreadyinstalled on a computer, are used to interrogate an identificationdevice, using ultrasound. Preferably, the computer's microphone is usedto detect a response from the interrogated device. In some embodiments,especially for toys, the interrogation may comprise audible sounds.Thus, in a preferred embodiment of the invention, cheap and/or simplecommunication between a device and another device or a computer isfeasible, since no special computer hardware is required. In addition,it becomes simpler to interface an input device with a computer programthat responds to that input device. Additionally or alternatively,ultrasonic communications may be used to download a program and or musicfile to a toy or other devices. Possibly, the program and/or music fileare directly downloaded from an Internet as sound files, possiblyreducing or obviating the need for a dedicated toy (or device)programming software interface. Possibly, the toy and/or device generatesounds in response, which sounds are transmitted back through theInternet.

In a preferred embodiment of the invention, the acoustic waves used forcommunication or, possibly, another set of acoustic waves, may be usedto determine the relative position and/or orientation of electronicdevices. In a preferred embodiment of the invention, a touch screen isemulated by interrogating a transponder on a pointing implement, usingbuilt-in speakers of an electronic device, to detect the position,orientation and/or motion of the implement, thereby identifying alocation which is “touched” or pointed to. In a preferred embodiment ofthe invention, the transponder is embodied using a speaker and amicrophone of the pointing implement, for example if the implement is acellular telephone.

For example, one or more of the following sound generators may beavailable in a personal computer: built-in speaker, modem speaker andsounds generated by mechanical devices, such as a hard disk drive or adiskette drive. These sound generators may also be used for transmittinginformation.

An aspect of some preferred embodiments of the invention relates tovisual communication between devices, using built in hardware. In oneexample a video camera, which is provided with many computers, can beused to accept visual signaling from a second device. Such visualsignaling may be temporal, for example by flashing a screen or a LED.Alternatively or additionally, the signaling uses a spatial code, forexample, by the remote camera identifying visual spatial patterns on ascreen, for example using OCR techniques. Possibly, the frequency offlashes is higher than perceived by a human observer, in order to reducedistraction. It is noted that communication between a screen and a videocamera enables a wide bandwidth and/or enhanced error correction, due tothe large number of transmission and reception pixels available.Alternatively or additionally, an existing IR port is used as a source,which source is detectable by many CCD cameras.

An aspect of some preferred embodiments of the invention relates tocommunicating with a device using RF, rather than acoustics. In apreferred embodiment of the invention, the RF generated by a computerspeaker, rather than the generated sounds, is detected by a seconddevice. In an exemplary embodiment, a smart-card detects the RFgenerated by a telephone loudspeaker, rather than sounds. Alternativelyor additionally, a device may induce electric fields in a microphone bytransmitting RF fields at ultrasonic or sonic frequencies. Alternativelyor additionally, a computer can produce measurable and encodableelectromagnetic waves by transmitting information on a plurality of databuses simultaneously, so that a stronger signal is detected outside thecomputer.

An aspect of some preferred embodiments of the invention relates todetecting the simultaneous generation of RF and acoustic pulses todetermine a distance between objects. If the two pulses are generatedsimultaneously, the delay between their detection is dependent on thedistance between the objects. The two pulses may be generated by asingle device, such as a computer speaker or they may be generated byseparate devices, such as a computer speaker and a BlueTooth RF link. Inan exemplary application, a computer speaker generates the two pulsessimultaneously and a microphone on a smart card detects two pulses, onecorresponding to the RF and one corresponding to the acoustics.Possibly, two sensors are provided on the card, one for each modality,however, a combined sensor, such as a piezoelectric microphone ispreferred. The processing may be on the smart card. Alternatively, theacquired signals may be forwarded to a computer for processing. Oneexemplary method of determining the delay is by autocorrelation of thereceived signal. The pulses used may be temporally symmetric orasymmetric.

An aspect of some preferred embodiments of the invention relates tousing a computer microphone to acquire ambient sounds, then analyzingthese sounds using a computer, and then using the analysis to determineevents occurring in its neighborhood. Optionally, these sounds aretransmitted to remote location, either as sound files or as data filesfor basic and/or further analysis. In a preferred embodiment of theinvention, electronic devices are designed and/or programmed to generatesounds (possibly in the ultrasonic range), which sounds represent theircurrent state or particular events. Thus, by eavesdropping on thesesounds it is possible to determine the status of electronic devices. Inone example, a malfunctioning fax machine will generate one hum and/oran arriving fax on an operating fax machine will generate a differenthum or sound pattern. A computer near the fax machine can determine thestatus and events and transmit this information, possibly using acomputer network, to a user of the information. In some cases, theexisting sounds generated by a fax (beeping, printing noises etc.) canbe identified by the computer, without need for special programming ofthe fax machine to generate novel sounds.

An aspect of some preferred embodiments of the invention relates tointerrogating an electronic device using an acoustic channel. Suchinterrogation should not adversely affect the operation of the devices.In one example, the device is a network component, such as a hub. Inanother example, the device is a computer. In a preferred embodiment ofthe invention, the acoustic channel is controlled by the computer(analysis of incoming information, generation of outgoing transmissions,and possibly execution of certain software) without interfering with thework of a person using that computer, for example word processing work.

An aspect of some preferred embodiments of the invention relates tocommunicating with a speaker and/or a microphone using non-airbornetransmission of the sounds. In an exemplary embodiment of the invention,sounds are transmitted over electrical cabling in a home, for examplebetween two wall sockets. In another exemplary embodiment, the casing ofa device and/or cables attached thereto are used to propagate sonic orultrasonic signals to a microphone or from a loudspeaker.

An aspect of some preferred embodiments of the invention relates to athin-client architecture in which a thin client is displays informationand/or transmits input to a controller of the thin client usingultrasonic waves. An advantage of such an architecture is that thecontroller may be any suitable electronic device which has a speaker,with some suitable software modifications or with a suitable hardwareattachment. In an exemplary application, a user can use a watch likeinstrument to display the status and/or control a home automationsystem. Alternatively or additionally, the watch can sound radiotransmissions (or other messages) which are forwarded by ultrasound tothe watch, for example by a computer with a radio card or by a digitalradio. Possibly, the instrument includes one or more inputs which can beforwarded to the controller, again, preferably by ultrasound. Theseinputs may be mapped to the controller's controls or they may interactwith suitable software at the controller. Although software execution onthe instrument is possible in some embodiments, it is not preferred.Alternatively or additionally, although acoustic transmission ispreferred, in some preferred embodiments of the invention RF or othertransmission methods are used.

There is thus provided in accordance with a preferred embodiment of theinvention, a method of communicating with an electronic device,comprising:

providing a computer having an audible sound receiving and generatingsub-system including a microphone;

transmitting from a source at least one ultrasonic acoustic signal,encoded with information to the computer; and

receiving said at least one signal by said microphone, to be detected bysaid computer.

There is also provided in accordance with a preferred embodiment of theinvention, a method of communicating with an electronic device,comprising:

providing a computer having an audible sound receiving and generatingsub-system including a microphone and a loudspeaker;

transmitting from a source at least one first acoustic signal, encodedwith information to the computer;

receiving said at least one signal by said microphone, to be detected bysaid computer; and

transmitting to said source, using said loudspeaker, at least a secondacoustic signal, encoded with information, in response with saiddetected signal. Preferably, at least one of said at least one firstsignal and at least a second signal comprise an ultrasonic signal.

There is also provided in accordance with a preferred embodiment of theinvention, a method of communicating with an electronic device,comprising:

providing an electronic device having a sound receiving and generatingsub-system including a microphone and a loudspeaker;

transmitting from a source at least one ultrasonic acoustic signal,encoded with information, to the electronic device;

receiving said at least one signal by said microphone, to be detected bysaid electronic device; and

transmitting to said source, using said loudspeaker, at least a secondultrasonic acoustic signal, encoded with information, in response withsaid detected signal. Preferably, said electronic device comprises acomputer.

There is also provided in accordance with a preferred embodiment of theinvention, a method of communicating with an electronic device,comprising:

providing a telephone having a sound receiving and generating sub-systemincluding a microphone;

transmitting from a source at least one acoustic signal, encoded withinformation to the telephone; and

receiving said at least one signal by said microphone, to be used tocontrol said telephone. Preferably, said acoustic signal comprises anultrasonic signal.

There is also provided in accordance with a preferred embodiment of theinvention, a method of communicating with an electronic device,comprising:

providing a computer having a sound receiving and generating sub-systemincluding a microphone;

transmitting from a source at least one acoustic signal, encoded withinformation to the computer; and

receiving said at least one signal by said microphone; and

forwarding an indication of said information to a remote computer, overan Internet. Preferably, said indication comprises a sound file.Alternatively, said indication comprises a data file.

In a preferred embodiment of the invention, said acoustic signalcomprises an ultrasonic signal.

In a preferred embodiment of the invention, said computer comprises aPDA, personal digital assistant. Alternatively, said computer comprisesa portable computer. Alternatively, said computer comprises a desk-topcomputer.

In a preferred embodiment of the invention, the method comprisesprocessing said at least one sound by said computer. Preferably,processing comprises extracting said encoded information. Alternativelyor additionally, said processing comprises determining a distancebetween said microphone and said source. Alternatively or additionally,said processing comprises determining movement of said microphonerelative to said source. Preferably, said movement comprises angularmovement. Alternatively or additionally, said movement comprisestranslation.

In a preferred embodiment of the invention, said processing comprisesdetermining a spatial position of said microphone relative to saidsource. Preferably, said spatial position is a one-dimensional spatialposition. Alternatively, said spatial position is a two-dimensionalspatial position. Alternatively, said spatial position is athree-dimensional spatial position.

In a preferred embodiment of the invention, said processing comprisesemulating a touch screen using said received at least one sound.Alternatively or additionally, said processing comprises emulating apointing device using said received at least one sound.

In a preferred embodiment of the invention, the method comprisescontrolling at least one action of a toy, responsive to said received atleast one sound.

In a preferred embodiment of the invention, said electronic devicecomprises a wireless communication device. Alternatively, said devicecomprises a toy.

In a preferred embodiment of the invention, said electronic devicecomprises a computer peripheral. Preferably, said peripheral comprises aprinter.

In a preferred embodiment of the invention, said information comprisesprogramming information. Alternatively or additionally, said informationcomprises music.

In a preferred embodiment of the invention, said source comprises a toy.Preferably, said information comprises stored player input.

In a preferred embodiment of the invention, said source comprises asmart card. Alternatively, said source comprises a wirelesscommunication device. Alternatively, said source comprises a computer.Alternatively, said source comprises a computer peripheral.

In a preferred embodiment of the invention, said information comprisespersonal information.

In a preferred embodiment of the invention, the method comprises logginginto a computer system responsive to said at least transmitted signal.

In a preferred embodiment of the invention, the method comprisestransmitting at least a second acoustical signal responsive to saidreceived at least one signal.

In a preferred embodiment of the invention, said acoustic signalcomprises human audible sound. Preferably, said sound has a mainfrequency over 10 kHz.

Alternatively, said sound has a main frequency which is infra-sonic.

In a preferred embodiment of the invention, said information is encodedusing below human-threshold amplitude signals. Alternatively oradditionally, said information is encoded using below human-thresholdamplitude variations.

In a preferred embodiment of the invention, said sound is generated at afrequency outside a normal operating frequency for said sound subsystem.Alternatively or additionally, said sound subsystem is designed forgenerating musical sounds.

In a preferred embodiment of the invention, said sound subsystemcomprises a sound card. Preferably, said sound card comprises aSoundBlaster compatible sound card.

In a preferred embodiment of the invention, said sound sub-system isdesigned for audible sound communication with a human operator.

In a preferred embodiment of the invention, said ultrasonic signal has amain frequency below 70, 60 or 50 kHz. Alternatively or additionally,said ultrasonic signal has a main frequency below 35 kHz. Alternativelyor additionally, said ultrasonic signal has a main frequency below 25kHz. Alternatively or additionally, said ultrasonic signal has a mainfrequency of about 21 kHz. Alternatively or additionally, saidultrasonic signal has a main frequency of about 20 kHz. Alternatively oradditionally, said ultrasonic signal has a main frequency of about 19kHz. Alternatively or additionally, said ultrasonic signal has a mainfrequency of below 18 kHz.

There is also provided in accordance with a preferred embodiment of theinvention, a method of creating a smart card terminal, comprising:

providing a general purpose computer having a general-purpose soundsub-system; and

loading a smart-card terminal software on said computer,

wherein said software controls said sound system to receive acousticwaves from a smart card and transmit acoustic waves to the smart card.Preferably, said software analyses said received acoustic waves todetermine information encoded by said acoustic waves. Alternatively oradditionally, said software retransmits said acoustic waves to a remotecomputer which analyses said received acoustic waves to determineinformation encoded by said acoustic waves. Alternatively oradditionally, loading a smart-card terminal software comprisesdownloading the software over an Internet. Alternatively oradditionally, said acoustic waves comprise ultrasonic waves.Alternatively or additionally, said smart-card comprises a memory forstoring a monetary balance. Alternatively or additionally, said softwareencrypts information encoded by said transmitted acoustic waves.Alternatively or additionally, said smart card comprises a memory forstoring identification information for a card owner. Alternatively oradditionally, said smart card comprises a processor for analyzinginformation received from said computer and for generating a response tosaid computer.

There is also provided in accordance with a preferred embodiment of theinvention, a computer system comprises:

a processor;

a sound sub-system, designed for generating music, comprising:

-   -   a speaker which generates acoustic waves; and    -   a microphone which detects acoustic waves;

a memory; and

a software installed in said memory, wherein said software analysesacoustic waves received by said microphone to recognize informationencoded by said acoustic waves and wherein said software uses saidspeaker to transmit information encoding acoustic waves responsive tosaid recognized information. Preferably, said acoustic waves compriseultrasonic acoustic waves.

There is also provided in accordance with a preferred embodiment of theinvention, a method of attaching a peripheral to a computer, comprising:

providing a general purpose computer including a sound generating andreceiving subsystem;

analyzing, at said computer, sounds received by said subsystem to detectacoustic transmissions from said peripheral; and

transmitting, from said computer and using said subsystem, informationto said peripheral using encoded sound transmissions.

There is also provided in accordance with a preferred embodiment of theinvention, method of communicating with a computer, comprising:

generating by a computer an electromagnetic field by driving a computercomponent not designed for field generation in a manner which generatesa parasitic electromagnetic field, wherein said field is encoded withinformation by said generation; and

receiving said encoded field by an electronic device. Preferably, saidelectronic device receives said wave using an RF antenna. Alternativelyor additionally, said electronic device receives said wave using amicrophone. Alternatively or additionally, said computer componentcomprises a speaker. Alternatively or additionally, said electromagneticfield has a main AC frequency of between 10 kHz and 100 kHz.

There is also provided in accordance with a preferred embodiment of theinvention, a method of detecting electromagnetic radiation by a computercomprising:

generating an electro magnetic field which encodes information;

sampling a microphone channel associated with said computer to detectartifacts caused by said field; and

decoding said information by said computer. Preferably, said associatedcomputer is physically connected to said microphone channel.Alternatively, said associated computer is connected to said microphonechannel by a computer network connection.

In a preferred embodiment of the invention, said electromagnetic fieldis a side-effect of driving a speaker. Preferably, said electromagneticfield is a side-effect of driving a speaker.

In a preferred embodiment of the invention, said electromagnetic fieldhas a main AC frequency of between 10 kHz and 100 kHz.

There is also provided in accordance with a preferred embodiment of theinvention, a method of emulating a microphone using a speaker,comprising:

providing a computer having a speaker channel and a microphone channel;

coupling a computer speaker to the microphone channel; and

receiving signals for said microphone channel via said speaker.Preferably, coupling comprises coupling using a coupler.

There is also provided in accordance with a preferred embodiment of theinvention, a coupler for an audio channel, comprising:

a first connector for selectively driving a speaker or receiving inputfrom a microphone;

a second connector for sending signals to a microphone channel;

a third connector for receiving speaker-driving signals from a speakerchannel; and

circuitry for selectively driving said speaker or receiving signals fromsaid microphone, using said first connector. Preferably, said circuitryreceives switching instructions via said speaker channel.

There is also provided in accordance with a preferred embodiment of theinvention, a method of determining a status of an electronic device,comprising:

receiving information encoding acoustic signals generated by saiddevice; and

analyzing said signals to determine an operational status associatedwith said device responsive to said information. Preferably, said statuscomprises a status of said device. Alternatively or additionally, saidstatus comprises a status of a second device attached by computercommunications with said device. Alternatively or additionally, saidstatus comprises a status of a network that said device is part of.Alternatively or additionally, said analyzing comprises analyzing on acomputer separate from a circuitry used for acquiring said signals.Alternatively or additionally, said signals are generated by said deviceresponsive to an interrogation by a second device which performs saidreceiving. Preferably, said interrogation does not interrupt otheractivities of said device.

Alternatively, said signals are generated by said device independent ofan interrogation by a second device.

In a preferred embodiment of the invention, said signals are sonic.Alternatively, said signals are ultrasonic.

In a preferred embodiment of the invention, the method comprisesprogramming an existing device to generate said signals using anexisting speaker which, when the device was designed, was not designatedfor communication with a second device. Preferably, said programmingcomprises software programming in which only memory storage locationsare modified. Alternatively or additionally, said programming compriseshardware programming in which electronic circuitry of the device ismodified.

In a preferred embodiment of the invention, said electronic devicecomprises a computer. Alternatively, said electronic device comprises anetwork hub. Alternatively, said electronic device comprises a networkswitch. Alternatively, said electronic device comprises a networkrouter.

There is also provided in accordance with a preferred embodiment of theinvention, a method of accessing a single user computer by a seconduser, without interrupting the activities of the first user, comprising:

transmitting an acoustically encoded command by the second user to thecomputer;

receiving said command by the computer; and

executing the command by the computer. Preferably, said command isultrasonically encoded. Alternatively or additionally, said receivingcomprises receiving using a microphone connected to a sound card of saidcomputer, which sound card is designed for audio applications.

There is also provided in accordance with a preferred embodiment of theinvention, a computer networking method comprising:

providing first, second and third computers; and

transmitting a message encoding data from the first computer to thethird computer via the second computer by acoustic transmission betweenthe computers. Preferably, said acoustic transmissions utilize soundcards designed specifically for processing audible sounds. Alternativelyor additionally, said acoustic transmissions utilize are ultrasonichaving a frequency of less than 50 kHz.

There is also provided in accordance with a preferred embodiment of theinvention, a wireless peripheral for an electronic device, comprising:

a microphone for receiving ultrasonic acoustic transmissions having afrequency of less than 70 kHz from an electronic device;

circuitry for processing said transmission; and

a display for displaying a result of said processing. Preferably, saidperipheral comprises an input element and a speaker for transmittingsound to said electronic device responsive to input from said inputelement.

In a preferred embodiment of the invention, said peripheral comprises aprinting engine for printing a result of said processing. Alternativelyor additionally, said processing comprises merely of converting thesignals from an acoustic encoding format to a format suitable for saiddisplay. Alternatively, said processing comprises processing theinformation encoded by said transmissions.

In a preferred embodiment of the invention, said electronic devicecomprises a computer. Alternatively or additionally, said electronicdevice comprises a radio. Alternatively or additionally, said peripheralcomprises a speaker for said electronic device. Alternatively oradditionally, said peripheral comprises a time display which presents atime signal generated by said electronic device. Alternatively oradditionally, said peripheral comprises a status display which presentsa status signal generated by said electronic device.

There is also provided in accordance with a preferred embodiment of theinvention, a wireless peripheral for an electronic device, comprising:

a speaker for transmitting ultrasonic acoustic transmissions having afrequency of less than 70 kHz from an electronic device; and

circuitry for generating said transmissions; and

an input element for receiving input to be encoded by saidtransmissions. Preferably, the peripheral comprises a microphone forreceiving ultrasonic transmissions from said electronic device.Alternatively or additionally, said input element comprises a bar-codereader. Alternatively or additionally, said input element comprises asmart card reader. Alternatively or additionally, said input elementcomprises a pointing device. Alternatively or additionally, said inputelement comprises a keyboard.

There is also provided in accordance with a preferred embodiment of theinvention, a method of communicating with a computer, comprising:

providing a computer having a data line attached to at least oneparticular peripheral;

sending a data transmission to the computer by injecting a signal intosaid data line using an electromagnetic coupler; and

identifying by said computer the source of said data transmission.

There is also provided in accordance with a preferred embodiment of theinvention, a method of communicating with a computer, comprising:

providing a computer having a data line attached to at least oneparticular peripheral;

generating by said computer a data transmission directed to a differentperipheral; and

receiving said data transmission from the computer by eavesdropping onsaid data line using an electromagnetic coupler.

There is also provided in accordance with a preferred embodiment of theinvention, a method of injecting data into a computer from an uncoupledperipheral, comprising:

transmitting said data from the uncoupled peripheral to a tap; and

physically activating a peripheral coupled to said computer, by saidtap. Preferably, physically activating comprises activating keys in akeyboard. Alternatively, physically activating comprises activatingvibrating a mouse.

There is also provided in accordance with a preferred embodiment of theinvention, a method of communicating with a computer, comprising:

generating by a computer a data transmission;

controlling, by said computer, a component not designated for datatransmission, to effect a transmission of said data; and

receiving said data transmission from the computer by a second device.Preferably, said computer controls an activation of a mechanicalcomponent of said computer to transmit said data by modulation ofmechanical sounds generated by said computer. Alternatively oradditionally, said computer controls an activation of a status LEDs ofsaid computer to transmit said data by modulation of illumination ofsaid LEDs. Alternatively or additionally, said computer controls anactivation of an electrical component of said computer to transmit saiddata by modulation of parasitic RF signals generated by said computer.

There is also provided in accordance with a preferred embodiment of theinvention, a method of transmitting data over a computer network,comprising:

providing a sound file at a first location;

transmitting said sound file to a second location via said computernetwork; and

transmitting said sound file as acoustic sounds to a processor at athird location.

There is also provided in accordance with a preferred embodiment of theinvention, a method of transmitting data over a computer network,comprising:

encoding data as acoustic sounds at a first location;

transmitting said sound file to a second location as acoustic sounds;and

transmitting said acoustic sounds as a sound file to a third location,via said network.

In a preferred embodiment of the invention, said network comprises anInternet.

There is also provided in accordance with a preferred embodiment of theinvention, a method of analyzing acoustic signals, comprising:

receiving said signals using a microphone which microphone converts thesignals into analog electrical signals;

driving at least one digital data lead of an integrated circuit usingsaid analog signals; and

processing said signals using said integrated circuit. Preferably, themethod comprises amplifying said electrical signals prior to saiddriving.

There is also provided in accordance with a preferred embodiment of theinvention, a method of determining a time of flight of a pulse betweentwo electronic devices, comprising:

simultaneously generating an acoustic pulse and an electromagnetic pulseusing a speaker of a first electronic device;

detecting, using a single detector associated with a second electronicdevice, both the acoustic pulse and the electromagnetic pulse; and

determining a time of flight of said acoustic pulse the two devicesbased on a delay between the reception of the two pulses.

There is also provided in accordance with a preferred embodiment of theinvention, a method of acoustic communication, comprising:

estimating an echo duration for an acoustic band; and

transmitting data using the acoustic band, wherein between data elementsa period of silence is provided, having a duration responsive to saidecho duration. Preferably, the data elements are encoded usingindividual frequencies in an FSK encoding protocol. Alternatively oradditionally, estimating comprises estimating based on an expectedcommunication geometry. Alternatively, estimating comprises estimating aduration based on at least one acoustic calibration generated adjacentto said data transmission.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more clearly understood with reference to thefollowing detailed descriptions of non-limiting preferred embodiments ofthe invention in which:

FIG. 1 is a schematic illustration of a computer and an electronicdevice that are operative to communicate using sound waves, inaccordance with a preferred embodiment of the invention;

FIG. 2 is a schematic illustration of two communicating electronicdevices, in accordance with a preferred embodiment of the invention;

FIG. 3 is a schematic illustration of a smart card communicating with acomputer, in accordance with a preferred embodiment of the invention;

FIG. 4 is a schematic illustration of a smart-card reader in accordancewith a preferred embodiment of the invention;

FIG. 5 is a schematic illustration of a method of tapping into acomputer, without requiring complicated installation of hardware, inaccordance with a preferred embodiment of the invention;

FIG. 6 is a schematic illustration of an unobtrusive computer checkup inaccordance with a preferred embodiment of the invention; and

FIG. 7 is a schematic illustration of a computer communication setupusing acoustics, in accordance with a preferred embodiment of theinvention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 is a schematic illustration of a computer 20 and an electronicdevice 30, which are operative to communicate using sound waves, inaccordance with a preferred embodiment of the invention. Most computerscurrently on sale include a sound system 24, usually a sound card,connected to at least one microphone 26 and at least one speaker 28.Many electronic devices include a microphone 34 and a speaker 36. In apreferred embodiment of the invention, computer 20 and electronic device30 communicate using these standard components, which are usually notdesigned for computer communication but for human communication. In somecases, the electronic device (or the computer) may include a jack towhich one or more speakers and one or more microphones may be connected.Preferably, such connected acoustic elements are positioned on adifficult to obstruct portion of the device, preferably at positionswhere the elements have a wide field of view.

In one preferred embodiment of the invention, a standard sound card,such as the popular “Sound-Blaster” is used to generate sonic and/orultrasonic signals to (and to receive them from) an electronic device, atoy and/or another object. The acoustic signal may be audible orinaudible, for example having mainly ultrasonic or infrasonicfrequencies. Preferably, frequencies of about 22 kHz and 24 kHz and 32kHz are used, since a standard sound card provides these sampling rates(and/or their multiples, e.g., 44 kHz and 48 kHz). As used herein theterm “main frequency” is used to describe the frequency band in whichmost of the energy of the information carrying signal is concentrated.In some cases, the information carrying portion of the signal is not atthe main frequency generated by the card, for example when an ultrasonicsignal is overlaid on a different audible sound.

In some preferred embodiments of the invention, a sound card is adaptedto work in the near ultrasonic range, for example by increasing itssampling frequency. Generally, the microphone and loudspeaker used for acomputer system can support low frequency ultrasound with sufficientfidelity without adaptation. In some cases however, a specialultrasound-sensitive microphone or ultrasound-effective speaker may beused. In other cases, the sensitivity of a particular microphone and/orloudspeaker may be determined prior to or during communication with anelectronic device. In one example, if a device having knowncharacteristics transmits an equally powerful signal at severalfrequencies, the frequency sensitivity (and/or directional sensitively)of a microphone may be determined. In a similar manner, a computer maygenerate these sounds and the signals detected by the device analyzed todetermine output characteristics of the particular loudspeaker used. Inaddition, a self-calibration procedure may be performed by listening tothe computer's output using the computer's microphone. In some cases,both the device and the computer sound systems can be calibrated bycombining self testing and cross-testing.

In some cases, the microphone and/or the sound card are sensitive enoughto receive, from the object, an RF signal associated with generating theacoustic signals, even if an acoustic signal is not sent (e.g., noloudspeaker is present). Alternatively or additionally, the object maydetect RF signals generated by the speaker or sound card whilegenerating the ultrasound. These RF signals are generally less affectedby lack of line of sight than ultrasonic signals. In an exemplaryembodiment, a device for communication with a telephone handset (orother devices where the speaker and microphone are displaced), can bemade small, by allowing the detection of sounds from the telephone to beemulated by the detection of RF fields from the telephone speaker. Thus,a smart-card can be made small and placed against the telephonemicrophone and still receive signals from the telephone loudspeaker.Alternatively or additionally, the device may transmit RF fields togenerate an electrical signals at the telephone microphone. Thesetransmitted and received signals may be ultrasonic or they may be sonic,for example DTMF or DTMF-like signals as known in the art.

In a preferred embodiment of the invention, such an acousticcommunication may be used to program a toy and/or retrieve informationfrom a toy, for example replacing an RF link for this purpose asdescribed in U.S. Pat. No. 5,752,880, the disclosure of which isincorporated herein by reference. In a particular embodiment, music maybe downloaded from the Internet, directly to the toy, for example bymodulating an ultrasonic signal to carry MP3 sound files. Alternativelyor additionally, such a link may be used for real-time communicationwith the toy.

Some embodiments of the invention do not require that the electronicdevice communicate with a computer. FIG. 2 is a schematic illustrationof two communicating electronic devices 30 and 30′. In one example, aPDA communicates with a printer. In another, an organizer communicateswith a satellite telephone. Possibly, such communication is used toexchange data files and/or to share capabilities, such as modemconnections. In some cases a port adapter may be required to be pluggedinto a port, for example a sonic-to-parallel adapter, which convertsbetween acoustic signals and parallel port signals.

A computer network, in accordance with a preferred embodiment of theinvention, utilizes sound waves transmitted between computers forcommunication, using existing hardware, such as an audio card,loudspeakers and a microphone. Preferably, the sound waves areultrasound waves. In a preferred embodiment of the invention, such acomputer network is used to connect a PDA or a portable computer to adifferent computer, for example for data transfer or for sharingperipherals, such as a modem, a printer or a storage device. Thus, anexisting PDA (which includes a loudspeaker and a microphone) can use amodem of a desk-top computer, without requiring additional hardware inthe PDA, possibly requiring only a small software change. This softwarechange may be in application software on the PDA or in the operatingsystem software (or both), depending on the implementation. In anotherexample an acoustic-enabled smart-card (such as that described below),can print, or backup information using a standard desktop computer.Alternatively or additionally, such a network may be used in a smalloffice, for example for file or printer sharing.

In a preferred embodiment of the invention, a standard communicationprotocol/language is defined, so that many types of devices cancommunicate and/or share resources using the standard language.Alternatively, an existing networking language may be used.

In a preferred embodiment of the invention, sonic and/or ultrasoniccommunication is used for paying a toll or a fee (human, package orvehicle), utilizing a reactive component, possibly a passivetransponder, on the tolled item. In another example, such communicationis used to pay a transportation fee, for example on a subway or a bus.Alternatively or additionally, an acoustic mechanism as described hereinis used to open vehicle barriers, for example at entrances to apartmentcomplexes or to open garage doors. Alternatively or additionally, theacoustic mechanism is used for automatic refueling/billing systems,possibly transmitting billing and/or mileage information to a pumpreceiver, controlling the fuel flow and/or verifying the fuel type.Possibly, a car dashboard speaker, a car horn, an alarm speaker, a carradio speaker or a dedicated speaker, is used to sound the requiredsonic and/or ultrasonic signals. In some cases, as noted above, it isthe RF signals generated by the speaker which are detected. In apreferred embodiment of the invention, a car radio speaker is made togenerate the required sounds by transmitting an electromagnetic wave tothe radio or to its loudspeaker, from a specialized electronic device.

Alternatively or additionally, to using a computer, in a preferredembodiment of the invention, a set-top box, of a cable TV system, forexample, is used to transmit and/or receive acoustic signals.Preferably, a microphone is connected to the set-top box. Alternativelyor additionally, the transmission back to the set-top box uses an IRsignal, which is detectable by the set-top box. In one example, theset-top box includes software that analyzes signals. Such signals maycomprise responses of electronic devices and/or toys to sounds generatedby the television or by the set-top box. Alternatively or additionally,the set-top box adds sounds (or ultrasonic waves) to a video and/oraudio stream decompressed by the set-top box. Alternatively oradditionally, the set-top box adds temporal and/or spatial opticalmodulations to a video stream, for an optically-sensitive electronicdevice to detect.

In a preferred embodiment of the invention, the detection of a signal byan electronic device (or a computer) comprises a binary detection of thesignal, e.g., an on/off state. Additionally or alternatively, morecomplex signal detection and analysis techniques may be implemented, forexample, detection of signal amplitude, frequency, frequency spectrum,Doppler shift, change in amplitude and/or duration, detection of anumber of repetitions, voice and/or other pattern recognition in thesound. Various information encoding protocols may be used, including AM,FM, PSK, QPSK and/or pulse length encoding. The transmitted signal mayinclude one or more of information about the sending device'sactivities, location, environment, nearby devices, locally sensedinformation, logic state, readiness, requests for information and/oranswers to such requests.

Such signal detection and/or analysis may also be performed on acomputer that is in communication with the electronic device. Thephysical detection circuit is preferably located on the device.Additionally or alternatively, the detection circuit is also located onthe computer.

In a preferred embodiment of the invention, microphone 34 (or microphone26) comprises a directional microphone, for example a stereophonicmicrophone or a microphone in which the frequency response is spatiallynon-uniform, to aid in determining the direction of the sound source orto reduce noise.

PCT application PCT/IL98/00450, titled “The Control of Toys and Devicesby Sounds”, filed Sep. 16, 1998, in the Israeli receiving office, thedisclosure of which is incorporated herein by reference, describes soundactuated toys. In particular, the application describes various soundmakers that generate sounds inadvertently as a result of motion, forexample beads in a box or noise form a crinkle material. Such a soundmaker is connected to and/or mounted on a toy, so that when the toymoves a signal will be generated for another toy or device to acquire.This PCT application also describes detecting the direction and/orposition of a sound, using directional microphones and/or a stereophonicmicrophone including two or more microphone elements. Additionally oralternatively, a relative distance is determined based on amplitude ofthe sound.

Israel application 127,569, filed Dec. 14, 1998, titled “InteractiveToys”, the disclosure of which is incorporated herein by reference,describes various toys and electronic devices which interact using soundwaves. These applications contain information useful in the design anduse of acoustically controlled devices, and which may be applied towardssome preferred embodiments of the invention.

FIG. 3 is a schematic illustration of a smart card 40 that communicateswith a computer. Although a smart card is a special case of anelectronic device, it is noted that typical smart cards do not includean acoustic input/output channel, especially not an ultrasonic one, inthe low ultrasonic frequencies.

In a preferred embodiment of the invention, smart card 40 comprises anacoustic element 42, a processor 44 that controls the acoustic elementand a memory 46 for storing information. Such a smart card may use asingle piezoelectric transducer (possibly a film layer) for bothtransmission and reception.

As many electronic devices include a speaker and/or a microphone, such acard may communicate with any such device that has suitable software.Due to the decreasing size of electronics, in some cases, a smart cardmay be emulated using a PDA or other electronic means (or vice-versa),with regard to both size and functionality. Additionally oralternatively, such smart card functionality may be exhibited by acellular telephone or a lap top computer. A benefit of a lap topcomputer and of a PDA is their convenient user-interface. A benefit of acellular telephone is the possibility of real-time and/or off-linecommunication with a central location.

A particular desirable use for such a smart card is for authentication,e.g., using a digital signature method, of e-commerce transactions. Insuch an application, the card may be used to supply encrypted or signedinformation, to a vendor, over the Internet or over the telephone, bytransmitting sound wave to the computer from the sound card. These soundwaves can forwarded to the vendor or a verifier as sound files or asdata files. The smart card may generate the information responsive toinformation presented by the computer, either acoustically to the smartcard or using a human to enter data into the sound file.

FIG. 4 is a schematic illustration of a smart-card docking station 110in accordance with a preferred embodiment of the invention. A smart card112 is inserted into the reader 110. A portion 114 of the reader isconfigured to communicate with the smart card, for example using RF,magnetic fields, ultrasound, IR and/or any other communicationprotocols. Possibly, a plurality of such areas 114 are provided, eachfor a different physical protocol. These communications with the cardare preferably transformed, using an acoustic transducer 116, intoacoustic communications to be transmitted to—and/or received by—a remotecomputer or other electronic device, using the methods as describedherein. Thus, an owner of a smart card can easily interact with astandard computer without installing a dedicated reader on the computer.Rather, the smart card owner will carry around a miniature adapter 110that can communicate with a computer in a wireless manner.Alternatively, a smart card may be constructed to have an ultrasoniccommunication protocol, such that swiping can be performed withoutrequiring a docking station 110.

Alternatively or additionally, docking station 110 is designedspecifically for magnetic cards, such as common credit cards. Station110 preferably includes a sensitive magnetic field detector in area 114,so that when a card is inserted into the docking station, the magneticstrip is read. Consequently, it becomes possible to swipe a standardmagnetic card at many existing electronic devices, without requiringspecial hardware to be connected. A dedicated station may be made verythin, for example less than 10 mm or even less than 5 mm. Preferably thedocking station has a closed configuration, but an open docking station,comprising a sensor and a contra to hold the card against the sensor isalso envisioned. Although card swiping is a one-way communicationprocess, in some cases two way communication may be desirable, forexample for a user to collect information regarding purchases forexample amounts, times, type and authentication confirmation. In someembodiments, this information may be accumulated by the station 110, asdescribed below.

Alternatively or additionally, station 110 may be adapted to attach to aport of a PDA, cellular telephone, “organizer” or other portableelectronic devices. Such a station converts electronic signals at theport to sonic and/or ultrasonic acoustic signals that can be recognizedby a computer.

A dedicated station may be manufactured for each device and smart cardtype. Alternatively, a single station may be constructed for multipledevice types and include an auto-sensing circuit for detecting the logicof the output port. One example of such a detection is by “transmitting”a known signal from the device and determining the setting which allowsthe station to detect that signal. Another example of automaticdetection is by automatically recognizing characteristics of the device,such as transmission amplitude or geometry. Alternatively, station 110may include a switch or other user interface for manually selectingbetween different types of electronic devices.

It should be noted that although acoustic communication is preferred forat least one communication direction (computer to smart-card orsmart-card computer) one or both of the communication directions mayutilize other technologies, temporarily or on a permanent basis. Forexample, the card may use the IRDA IR communications standard or theBluetooth RF communications standard. Alternatively, one of thedirections may be manual, for example a device displaying to a user whathe should enter into the other device.

In some embodiments of the invention, station 110 may enhance thefunctionality of a device or a magnetic card, possibly elevating itsfunctionality to that of a smart card, or enhancing the functionality ofa less versatile smart card. For example, station 110 may provideauthentication of vendor, by decoding an encrypted signal transmitted bythe vendor (which a magnetic card is unable to read and/or process). Inanother example, station 110 may comprise a memory for tracking the useof a magnetic card. In another example, station 100 may providepositioning capabilities.

In a preferred embodiment of the invention, spatial angles between asound source and a plurality of microphones are determined by analyzingphase differences at the microphones. Alternatively or additionally,other methods known in the art may be used for positioning. In apreferred embodiment of the invention, a relative location of a pulsingsound source and a plurality of microphones is determined by solvingtime of flight equations. Thus, the relative location of an electronicdevice and/or a computer, relative to another electronic device or smartcard, may be determined and used to control the operation and/orcooperation of one of the above electronic devices.

In a preferred embodiment of the invention, four microphones are used todetermine a three-dimensional position. For a source at r=(x₀,y₀,z₀) anda plurality “i” of microphones at M_(i)=(x_(i),y_(i),z_(i)), thedistances between the source and the microphones are D_(i)=∥r−M_(i)∥.The acoustic velocity, “c”, may be known, for example based on a knownvelocity in air. Alternatively, it may be determined by measuring thetime of flight between a sound source and a microphone having fixed andknown relative locations. A difference between distances is preferablydefined as dD(i,j)=Di−Dj=c*dt(i,j), where dt(i,j) is defined as adifference between time of arrival at microphone i and time of arrivalat microphone j. For N microphones there are N-1 independent differencesdD. In an optimal configuration, the four microphones located atvertexes of a tetrahedron may be used to determine the location of asource. From practical considerations, such an arrangement may not bepossible. Preferably, more than four microphones are used, so that ahigher resistance to noise and/or a higher localization precision may beachieved. In a preferred embodiment of the invention, the threedimensional position is determined by numerically or analyticallysolving three equations of the form:dD=c*dt(i,j)=∥r−M _(i) ∥−∥r−M _(j)∥,where (i,j) is preferably selected to be (1,2), (2,3) and (3,4). Howeverany other independent three pairs of microphones may be used. In somecases it is useful if one of the electronic devices operates as atransponder, which receives signals and sends back a signal indicativeof the received signal and/or its time of flight.

In some embodiments of the invention, the above positioning method maybe applied using passive tags on the object whose position is to bedetected. In a preferred embodiment of the invention, such tags arepowered by the computer speaker, using an RF field generated by thespeaker. Alternatively, other RF-generating computer components may beused. this powering may be used to allow the tags to be responsive.Alternatively, this powering may be used for other uses. Alternatively,the powering may be by using a standard smart-cart RF-couplingperipheral.

Position determination may be based on transponding signals whichimpinge on objects. Alternatively, an object may transmit a signal whichencodes the time of arrival of the interrogating signal. Thus, theaccuracy of positioning can be higher than the frequency of theinterrogation signal, assuming the object has a clock with a higherresolution than the frequency of the interrogation signal.

A touch screen in accordance with a preferred embodiment of theinvention utilizes acoustic transmission to detect the location of atouch implement, such as a pen. In a preferred embodiment of theinvention, the position of the pen is determined using one or moremicrophones and/or speakers mounted on the pen, which transmit and/orreceive signals from a computer and/or other speaker and/or microphonecontroller. Possibly, a three-dimensional position of the touchimplement is determined using four acoustic elements, such as twomicrophones and two speakers. It is noted that a computer typicallyincludes a modem speaker, an internal speaker and/or optionally akeyboard speaker, as well as sound-card speakers. Lately, however, theinternal speaker is not provided in standard installations. In addition,some computers include an ultrasonic pointing device or other ultrasonicports. In a preferred embodiment of the invention, the smart card cancommunicate using this ultrasonic communication port.

A more basic type of position detection may be based on detecting aninterruption by an object of an ultrasonic beam between a speaker and amicrophone.

Alternatively or additionally to position detection using a responsiveobject, a radar-type position or distance detection may be used, inwhich a microphone of a computer detects the reflection of ultrasonicwaves from an object, which waves are generated by a computer speaker.By detecting only relative differences between reflections fromdifferent objects, the relative distances of the objects can bedetermined without knowing the exact location of the sound source.

In some preferred embodiments of the invention, the microphone detectsboth an acoustic pulse and an electromagnetic pulse generated as a sideeffect of producing the acoustic pulse. As the electromagnetic pulse issubstantially simultaneous it may be used as a clock or as a referencetime for determining the time of flight of the acoustic pulse.Additionally, since a transponder microphone may detect both kinds ofpulses, it is possible to determine the component times of flight to atransponder and not just the sum time of flight, using a retransmissionof the detected signals by the transponder.

In a preferred embodiment of the invention, location methods utilize acalibration process, in which the located implement is placed at one ormore known location, so that it is possible to correct for the locationof the speaker(s) and the microphone(s)/Alternatively or additionally,the calibration procedure is used to correct for propagation times (ofthe acoustic waves and/or of electronic signals which generate sounds)and/or for reflections, wavelength dependent attenuation and/orbroadband attenuation.

A different type of touch screen, in accordance with a preferredembodiment of the invention, detects the location of a touch implementbased on the detection and position determination (2D or 3D) of soundsgenerated when the touch implement touches the “touch sensitive”surface. This surface may be coated with a sound generating material,such as crinkle-paper, to provide a distinctive sound.

In a preferred embodiment of the invention, for example as describedabove, an interrogated object receives the ultrasound signal and sendsit back to a microphone of the computer. In a preferred embodiment ofthe invention, the computer analyses the time of flight and/or otherattributes of the transmission and determines a distance from, positionto, velocity of motion and/or other spatial attributes of the object. Insome cases, a plurality of sources or receivers may be placed on theobject, to assist in determining angular motion of the object.Alternatively or additionally, Doppler analysis of the response may beused to detect changes in distance. Alternatively or additionally,changes in distance are detected by comparing two consecutive measureddistances. The plurality of sources may be differentiated, for example,by timing of signal generation, frequency band used and/or encoding ofthe transmitted signal.

In a preferred embodiment of the invention, the object respondsimmediately to the interrogation signal. Alternatively, the objectdelays its response to an interrogation signal, for example for a fewmilliseconds. Alternatively or additionally, the object transmits at adifferent frequency from the received frequency, for example at 24 kHzin response to a 20 kHz query. Alternatively or additionally, the signaltransmitted by the object is received by a transducer which thentransmits the signal to the computer, for example acoustically or usingelectromagnetic coupling. Alternatively or additionally, the object mayrespond with an identification code. Alternatively or additionally, theobject modulates its transmission with an envelope, which envelopepreferable serves as an identification code and/or for transmission ofinformation regarding a status of the object, for example a position ofan arm of a toy. In some cases, the object relays information from amore remote object. In the case of identification, the object may sendan ID code even without prompting from the computer, for exampleperiodically or by a user pressing a button on the object (or by flexingthe object).

In a preferred embodiment of the invention, the object amplifies thesignal it receives using a discharge of a coil through a transistor,where the transistor serves as a variable resistor and/or as a wave-formcontroller.

In some preferred embodiments of the invention, the generated sounds aretransmitted indirectly via an existing network. One example of asuitable network is a telephone network, preferably a digital network,with the sounds being forwarded from one telephone to another. Anotherexample of a suitable network is an intercom system. Another example ofa suitable network is a LAN or an Internet. Additionally, as describedbelow, the ultrasonic waves may be transmitted (as acoustics, notelectromagnetic) over wiring, such as electrical wiring or over pipes,such as water and gas pipes.

In a preferred embodiment of the invention, a wireless telephone systemuses handsets which communicate with base stations, for examplecomputers or telephones, using ultrasonic communication, as describedherein. In a preferred embodiment of the invention, an office telephoneor computer network can serve as a local cellular network forcommunication, by keeping track of which base-stations are incommunication with which handsets and by providing the ability for abase station to locate handsets and for a handset to change basestations.

In many situations, there will be more than one active smart card (orother electronic device using ultrasonic waves for communication) in aregion at a single time. In a preferred embodiment of the invention, thedifferent devices coordinate so that they do not both transmit at a sametime. In one example, a central computer assigns time, frequency orcoding (CDMA) slots. In another example, an ALOHA algorithm is used toavoid collisions.

Some embodiments of the present invention contemplate other methods ofcommunication with a computer (or other devices) without installinghardware. FIG. 5 is a schematic block diagram of a communications tap102 for a computer 100, in accordance with a preferred embodiment of theinvention. In the configuration of FIG. 5, a tap is preferably placed oncommunication line to an existing peripheral 104. Thus, a user may notbe required to even access a back part of a computer, let alone acomputer's internal workings. An electronic device 106, a toy and/or asmart-card preferably send and/or receive signals from tap 102.Additionally or alternatively, device 106 may use one tap for receivingand one for sending. Possibly, a device uses taps only for one directionof communication.

In a preferred embodiment of the invention, the tap is placed on a cableto a printer, a network cable, a camera cable and/or a SCSI connection.Additionally or alternatively, the tap is placed on a serial cable, forexample a mouse cable. Additionally or alternatively, the tap is placedon a modem line, for example on a telephone line or by plugging the tapinto another telephone socket, to be received by the modem. Additionallyor alternatively, the tap is placed on a game controller line.Additionally or alternatively, the tap is placed on a loudspeaker line.This type of tap can detect signals that cannot be reproduced by theloudspeaker, for example very high frequencies, for example higher than50 kHz. Additionally or alternatively, the tap is placed on a microphoneline, possibly using the microphone line and/or the microphone itself asa sonic, ultrasonic or non-acoustic antenna (e.g., RF). Additionally oralternatively, the tap is placed on a display cable line.

In a preferred embodiment of the invention, the tap includes anelectromagnetic coupler, which can induce signals in a cable that passesthrough or near the tap. Additionally or alternatively, the tap candetect signals in the line and transmit them to device 106. In apreferred embodiment of the invention, the signals are at a differentcarrier frequency and/or signal frequency than the usual signals passedalong the line. Additionally or alternatively, the signals travel in anopposite direction (input signals on an output line, such as a printeror output signals on an input line, such as a mouse). Additionally oralternatively, the signals encode information which information isdetected and removed from the data stream in the computer. Additionallyor alternatively, the signals are asynchronic on a synchronic line.Additionally or alternatively, the signals are transmitted only when nosignal is expected by the computer and/or the peripheral.

In an alternative embodiment of the invention, a piezoelectric actuator(or other vibrating element) is connected to a mouse (or a microphone).The actuator causes the mouse to shake at an amplitude of one or twoscreen pixels (or less) and the shaking is detected by software in thecomputer as signals from the toy. A return signal may be transmitted toa tap associated with the actuator, along the serial cable, with thesignal preferably being coded to be recognized by the tap and/or ignoredby the mouse.

In an alternative embodiment of the invention, device 106 sends signalsto computer 102 using a tap which actuates keys on a keyboard attachedto computer 100. Such actuation may be, for example, mechanical ormagnetic (e.g., on magnetic switched keyboards). Preferably the key usedis a shift key. Additionally or alternatively, signals from the computerare detected by detecting illumination of LEDs on the keyboard, forexample a “Num Lock” LED.

Alternatively or additionally, the tap detects illumination of otherLEDs on a computer, for example power, sleep, CD-ROM and/or hard diskLEDs. Alternatively or additionally, the tap detects informationtransmitted via noise or vibration generated by activation and/ormodulation of the activity of mechanical components of the computer, forexample diskette drives, disk drives and CD-ROM drives. Alternatively oradditionally, the tap detects an electromagnetic signal generated bypower surges to the devices, for example a CD-ROM when it is powered orvariations in RF amplitude and/or frequency of the CPU, for examplethose caused by entering a sleep mode.

In a preferred embodiment of the invention, a tap “learns” theelectromagnetic and/or acoustic profile of a particular computer orportion thereof and learns the effects of various commands on thisprofile. When a computer desires to communicate with a tap, itpreferably modifies the profile using those commands which aredetermined to have the greatest, most noticeable and/or fastest effecton the profile.

Additionally or alternatively, device 106 utilizes a transducer whichplugs into a parallel port, a serial port and/or is optically coupled orplaced near an IR port. Preferably, the transducer is a pass-throughtransducer, through which a printer and/or other peripherals maycommunicate normally with a computer. This transducer can then transmitthe signals by wired or wireless methods to a remote device.

In a preferred embodiment of the invention, the tap and/or transducercan automatically detect which type of cable is tapped/port is connectedto. Such a tap preferably includes a microprocessor or an integratedcircuit to analyze signals on the cable, rather than solely a transducerfor coupling signals to and from the cable. Preferably, such detectionis by analyzing amplitude, frequency and/or synchronization of signalspassing through the lines. Additionally or alternatively, the computerdetects which line is tapped, by detecting particular inferences on thatline. Alternatively or additionally, software on the computer sends testsignals along the lines, to be detected by the tap. Possibly, the tapcan detect the signals even without being programmed with the type ofline on which the signals are transmitted. Alternatively, when a tap isused, a configuration program is run so that a user can define to thetap and/or the computer what is being tapped.

In a preferred embodiment of the invention, a smart card directly tapsthe computer, for example using a RF antenna embedded in the smart cardto detect signals being transmitted over data lines, e.g., to aperipheral or another computer or for the use of the smart card.

In an exemplary embodiment of a device using tapping, a pass-throughhasp is provided, which is connected to a port. In a preferredembodiment of the invention, the hasp uses power from the power linesbut does not interact with data flowing through the port. Authenticationof software using the hasp preferably utilizes acoustic communicationbetween the hasp and the computer's microphone and/or speaker.Alternatively, the hasp may interact with signals that flow through theport, which signals are not suitable for use as data, for example thesignals using a wrong protocol, having an incorrect CRC, beingasynchronous in a synchronous connection or having an incorrectfrequency. Such a hasp may also be used to protect an easily stolendevice, such as a PDA or a laptop computer, which can use their internalspeakers and/or microphones to detect the proximity of a required IDtag. If the ID tag is not detected the device can fail to work, workincorrectly or it can report that it is stolen.

In a preferred embodiment of the invention, suitable software isinstalled on computer 100. Preferably, the software is self installing.Preferably, the computer is not used for any other use while device 106is communicating with it. Additionally or alternatively, the softwarecan differentiate between “regular” signals and signals related to thetap. In one example, a provided keyboard driver may detected specialcodes and/or data sequences on the keyboard line and remove them fromthe received data, passing only the rest of the received data to anoperating system of computer 100. Additionally or alternatively, aprovided mouse driver may detect spurious and/or small mouse movements,and recognize them as being tap-related signals, as described above.Additionally or alternatively, a printer driver can recognize data onthe cable as not coming from the printer but from a tap. Additionally oralternatively, data sent to the tap is preferably sent as data whichwill be rejected or ignored by the peripheral, for example havingincorrect parity settings or other intentional errors. Alternatively oradditionally to using a tap for communication with a toy, such a tap maybe used to attach a peripheral to computer 100. As indicated above, thetap may include a processing element so that the signals coupled to thecables do not interfere with the normal operation of the cable, forexample being transmitted when there are no others signals on the cable.Alternatively, such processing may be performed by a device which usesthe tap.

In a preferred embodiment of the invention, the signal received on thecomputer is used to modify an executing program and/or to generatecommands to other electronic device, preferably using sounds generatedby the computer but possibly using a dedicated connection. In anexemplary application, a computer game in which a computer displayresponds to external sounds, such as bowling pins falling, is provided.

The acoustic communication may also be used to communicate between aninput device and a computer program, for example between a wirelesskeyboard or mouse and a computer. In another example, a light-pentransmits to the play-station a signal responsive to pixel intensitieswhich are detected by a photo-detector thereon. Alternatively oradditionally, a synchronization signal is transmitted from a computerand/or a set-top box to the pen, to synchronize the pixel detection withthe TV raster scan. These transmissions may be additional to—oralternative to—transmission of position and/or orientation.Alternatively or additionally, the input device transmits the status ofcontrols thereon. Alternatively or additionally, the transmission isused to transmit information to be displayed on an output device or anoutput portion of the input device, for example to light up lightsthereon and/or drive text and/or graphics displays thereon.

FIG. 6 is a schematic illustration of an unobtrusive computer checkup inaccordance with a preferred embodiment of the invention. A user 142 isusing a computer 140. A user 146 wishes to interrogate computer 140, forexample to analyze a networking problem. In a preferred embodiment ofthe invention, a smart card 144 (or other electronic device) cancommunicate with computer 140 using an acoustical- or a tap-channel asdescribed above, without interfering with the activities of user 142.Alternatively or additionally, smart card 144 may be used to interrogatean interface-less device, such as a hub 148. One advantage of acousticalcommunication for these uses is that they do not generate a considerableamount of RF interference and do not require major (if any) changes in a(significant) install base of hardware. In a preferred embodiment of theinvention, hardware devices, such as hub 148 and computer 140continuously “hum” their status, in RF or in acoustics, so that thestatus can be discerned by eavesdropping on the hum, without needing tointerrogate the hardware.

A card such as card 144 may also be used to give privileges to it'sowner in the form of better service (e.g., priority at a file server,speed of connection to the Internet) and/or alleviate various securityrestrictions. For example, a manager can come to his employee desk,activates his card and previously unreachable files become available. Itis noted that this process of changing the behavior of a computer doesnot require logging on to the computer (although such log-on ispossible). Rather, the computer recognizes the manager even while itremains logged on to the other user.

In a preferred embodiment of the invention, when the card or otherdevice is used for logging-on, a hysteresis-type logic is used, in whichlogging on requires a high quality definite signal, while logging-off(possibly automatic log-off) is delayed until there is substantially nocontact with the card. The lack of contact can be detected by the lackof detection of a periodic signal generated by the card. Thus, oncelogging on is achieved, maintaining the contact does not require a highquality connection.

FIG. 7 is a schematic illustration of a computer communication setupusing acoustics, in accordance with a preferred embodiment of theinvention. A computer 152 includes a microphone 156 that is used fordetecting activity sounds of other electronic and/or mechanical devices.The activity sounds may comprise natural sounds, for example a pagesorter being used in a photocopier. Alternatively or additionally, theymay comprises indicator sounds, for example a beep generated by a faxmachine 150 when a fax comes in. Fax machine 150 may be connected to acomputer (as shown) or it may be unconnected. Alternatively oradditionally, they may comprise artificial sounds, for example a specialinformation carrying sound generated specifically for the benefit ofcomputer 152.

In a preferred embodiment of the invention, a computer 152 transmitsindications of the sensed activities to a remote computer, such ascomputer 154. Thus, a user at computer 154 can be informed of a faxcoming in or of an unanswered telephone call even if he is in adifferent room and the fax machine is not connected to a standardcomputer network.

Alternatively or additionally, the analysis of sounds detected bymicrophone 156 can be used to determine other occurrences at computer152. In one example, microphone 156 can be used to log the habits of auser, including, telephone conversations, numbers dialed (by detectingthe DTMF sounds), sounds of papers being shuffled, breathing sounds,snoring of a sleeping user, average number of rings until a call isanswered, and typing habits. Alternatively or additionally, microphone156 can be used to detect an occupancy of a room or glass breakage,possibly serving as a burglar alarm.

Alternatively or additionally, the microphone may be used to detectelectromagnetic impulses generated by operating devices. Typically, eachdevice has a different electromagnetic signature. Different signaturesmay be generated when the device is switched on or off, when the deviceis operated and/or for different modes of operation. Thus, acomputer-microphone combination can be used to detect the operation ofdevices, such as photocopies, door chimes and computers. In a preferredembodiment of the invention, a video input card is used to analyzehigher frequencies of electromagnetic radiation than those detectable bya microphone-sound card combination. It can thus be appreciated thatnoise signals which are usually rejected by signal processing algorithmsmay be analyzed to detect important information of activities in thevicinity of the microphone.

In an exemplary device which communicates with a computer usingultrasound, input/output filtration circuits are provided. Thesefiltration circuits preferably comprise op-amplifiers with filters forspecific frequencies for input and output, dependent on thecommunication protocol used. If non-audible frequencies are used, thefilters should preferably decrease or block power at audiblefrequencies, to reduce annoyance of a user.

The communication protocol is preferably a digital binary code in whichthe bits are transmitted using Frequency Modulation, Pulse WidthModulation, On-Off Keying and/or any combination of the above. Errorcorrection codes, for example parity, Gray or Hamming codes, as known inthe art may be used. It should be noted that the range of availablefrequencies may be limited if ultrasonic frequencies are used, due todegraded capabilities of the computer sound card.

In a reception process, the signals received by the device are convertthem to data bits, either by time domain analysis or by Fourieranalysis. Thereafter, error checking is preferably performed. Thereceived information may be decrypted (if necessary). Alternatively oradditionally, the received information may be encrypted, verified and/orsigned, in order to be stored in local memory. The local memory maycomprise ROM, RAM, EPROM, EPROM and/or other types of memory as known inthe art. Information to be transmitted may be encrypted beforetransmission.

The software on the computer receives a detected signal, filters it, andopens the protocol. Preferably, the software reduces noise using IIRband pass and/or low pass filters.

The received and filtered signal is then demodulated, into data bits,for example, by time domain analysis or by Fourier analysis. Datatransmission errors are preferably corrected. The data may then belocally analyzed and/or transmitted to a remote location, for example aseller's computer. In some embodiments, this software is written in anInternet Language, such as Java or ActiveX.

In a preferred embodiment of the invention, the acoustical detectionuses the maximum resolution and/or sensitivity afforded by themicrophone, i.e., going below the noise threshold as defined for audiouses. Alternatively or additionally, repeating and/or periodic ambientsounds are detected and removed or disregarded from the input signal. Ina preferred embodiment of the invention, ambient sounds arecharacterized as such during a calibration step which may be performedperiodically.

In some cases one or more of the following problems may be encountered,including: echoes, interference (acoustic or electromagnetic), and, athigher frequencies (>10 kHz), problems of directionality and weakreception. In addition, many microphones and speakers behave badly or inan unstable manner at these frequencies. It is noted, that by detectingRF rather than acoustic signals, acoustic interference is reduced and/orthe reception may be less sensitive to range and directionality. In apreferred embodiment of the invention, the received sound signals areprocessed using known signal processing techniques, such as filtration,equalization and echo cancellation. Preferred modulation methods usedinclude PWM, FSK, QPSK and on-off keying. Preferred frequency band typesinclude a single band, a wide band spread-spectrum and frequency hoppingbands. Preferred protocols utilize one or more of start-stopsynchronization bits, and constant and/or variable length messages.Possibly the device and/or the computer include logic for determiningthe exact frequency used for transmission, for example to correct forfrequency hopping, for frequency shifts caused by inaccurate manufactureand/or for environmental effects. Error detection methods may be used,for example, CRC (preferably 32 bit), Parity, Checksum, Blowfish,Hamming Codes, Retransmit/BCD Codes and Gray codes.

In a preferred embodiment of the invention, periods of silence areprovided between data bits in protocols other than on-off keying. In oneexample, an FSK protocol is provided with silence between the frequencypulses. Preferably, the duration of the silence is sufficient so thatechoes (or other artifacts) from the original pulse do not overlap witha next pulse. This period may be fixed, for example based on an expectedgeometry of the electronic devices and where they are used.Alternatively, the protocol may be adapted based on the instant echosituation. Alternatively or additionally, the pulse duration may bemodified to overcome noise, echo and/or other transmission problems. Ina preferred embodiment of the invention, a few calibration pulses arefirst sent to determine a desired silence and/or pulse duration.Possibly, different such durations are used for the two communicationdirections.

A feature of some embodiments of the invention is that a device cancommunicate with another device or computer over medium distances, suchas 0.3-20 meters, more preferably, 2-10 or about 7 meters.

Several variations on the reception at the computer (or other electronicdevice) may be practiced according to some preferred embodiments of theinvention, including: (a) using a regular microphone and sound card; (b)using a regular sound card but with a special microphone (e.g., one thatcan be tuned to specific, even ultrasonic, frequencies); (c) using aspeaker that can also be a microphone (one possibility is described indetail below); (d) using a microphone/receiver that connects to adedicated channel such as an RS232 or parallel port, and that canoptionally obtain power from the port; and (e) using a built indedicated hardware port that can be implemented on the computer board.

Several variations on the transmission from a computer (or otherelectronic device) can also be practiced, including: (a) using one ortwo speakers, powered alternatively or possibly powered together, forexample to increase the total power, to aid in noise cancellation and/orto aid in detecting echoes; (b) using an acoustic transducer connectedto a standard port or possibly tapping the computer, as described above;thus, there may be no need for a sound card in the computer; and (c) assuggested above, at small distances there appears to be an overlapbetween acoustic and electromagnetic signals both with regard totransmission and with regard to reception. Thus, possibly some of thesignals are transmitted and/or detected using RF antenna, or acousticsignal generation is detected using an acoustic antenna (or RF antenna)that detects the RF signature of the transmission. Alternatively oradditionally, the RF is used as a backup for the acoustic channel.

In some cases, for example if the receiver has a reduced computingcapacity, the incoming audio stream is sampled at lower than the carrierfrequency. However, a side effect of such sub-sampling, especially whenthere are no anti-aliasing filters, is that there may be confusionbetween audible and ultrasonic sounds. Thus, more complex processing maybe required to assure that the data transmission is acceptable. In oneexample, synchronous detection or a more robust error detection methodis used. Alternatively or additionally, a specialized waveform withunique time/spectrum characteristics is used, for example one thatrepeats itself at both 1 and 4 kHz after the down-sampling. Thus, it canbe better differentiated from the background.

In many cases, a speaker is available for a computer but a microphone isnot. In a preferred embodiment of the invention, a speaker is used as amicrophone. Preferably, the speaker is connected to the microphone portand/or line in port of a sound card, possibly through an adapting unit.Apparently, many speakers can operate as a microphone if they are notconnected to a power source. Preferably, an adapting unit is provided,for example to serve for buffering, switching (between microphone andspeaker functions) and/or for amplitude protection. In some embodimentsthe adapting unit periodically checks for an incoming signal fromoutside the speaker or for a signal from the speaker channel.Alternatively or additionally, the computer may generate a specialsignal via the speaker channel or possibly an audible signal to indicatethat a mode switching is desired. In one embodiment, the speaker isconnected in parallel to both microphone and loudspeaker channels, withelectronic protection for the microphone so that the power to thespeaker does not harm the channel.

Alternatively or additionally, some microphone types may be used as botha microphone and a speaker, if they are suitably driven. Possibly, acoupler is provided for driving the microphone using the speaker channeland/or for automatically switching the microphone between modes based onthe detection of an incoming signal or possibly periodically.

In some embodiments, the coupling device can split the frequenciesbetween the microphone and speaker functions, allowing a single elementto operate simultaneously as a speaker and a microphone. For example,low frequencies are used for the speaker and high frequencies are usedfor the microphone. When a high frequency is detected by the coupler, itis passed to the microphone channel, when a low frequency is detected itis sounded on the speaker.

Another aspect of the invention relates to transmitting acoustic signalson solid cables, rather than in the air. Such cables can includecomputer, communication and telephone cables, as well as electric powercables, for example inside a house. In a preferred embodiment of theinvention, the transmission along these cables is conducted to amicrophone of the device, to which it is directed, where thetransmission is analyzed. Alternatively or additionally, transmission isvia the box of the device and into the cable. Alternatively oradditionally, a dedicated coupler to the cable is provided for one orboth of the transmission and reception.

It is noted that a standard house is filled with this infrastructure inthe form of power supply, water pipes, telephone lines, and cables. Theultrasonic receiver/transmitter device is simple low-cost and can bevery small. The method can be used to achieve communication for low costappliances, or to achieve a higher bandwidth of information. The methodpermits multiple appliances talking together, broadcast of informationand a network of smart appliances. It can be used to communicate alsobetween computers, televisions and/or VCRs. Every device can have itsown id-number and a computer can control the operation of these devices.For some devices a dedicated controller is required, which receives theacoustic signal and, responsive to it, controls the device. Exemplaryuses include ordering shutting off or lighting lights at certain time(by computer control) or from outside of home (by telephone or networkto the computer) and ordering the VCR and/or television to cooperate inrecording a specific TV program, again preferably under computercontrol.

In a preferred embodiment of the invention, a reader-type input devicecan read external static (as opposed to sound waves and temporalpatterns) information, which information can be forwarded to anassociated computer or another device. Such an input device may also beintegrated with a smart-card. A simplest example is a wireless bar-codereader that reads bar codes and transmits them acoustically to acomputer, preferably using methods as described herein. Preferably, thebar-code reading capability is embodied in a smart card, so that amultifunction device is provided. Alternatively, a miniature device,such a ring, is manufactured, for convenience or a user. Such a devicemay be useful during purchasing, to allow a user to review large and/orpersonalized information regarding a product. Another example is amagnetic strip reader which transmits read magnetic strips to thecomputer. In the case of a magnetic strip reader, a single magneticsensor (or line sensor) may be sufficient, with the computer processingthe detected signals to correct for non-constant motion of the sensorover the magnetic material.

In one exemplary use, when the input device reads a tag, such a code ora description of a device, an associated computer switches to a WWW pagewhich displays details associated with the read information. Thecomputer may be a hand-held computer or PDA. Alternatively, the computeris a standing or store provided computer. Alternatively, the computer ison another side of a telephone line, which acoustic signals aretransmitted over the telephone line to the computer, to cause certainspeech to be transmitted back. Alternatively or additionally, such tagsmay be used for technical support (e.g., each home device or componenthas such a code and there is a help file or scripts associated with thecode). Alternatively or additionally, such tags may be used for customerrelations, for example to provide information to an interested user. Insome types of products, the computer and/or the tag reader can controlthe product using information read for the tag. An exemplary situationis a computer device, on which a tag reader or a same or second computercan execute a diagnostic program responsive to the read tag.

An exemplary device consists of an acoustical transmitter, a tag-readingelement, and some control logic. The type of tag reading element useddepends on the type of tag, for example, if it is optical or magnetic.The tag itself may include bar codes, other optical coding or even text.In a magnetic example, the tag may comprise magnetic ink. Preferably,but not essentially, the tags are of a type that can be printed usingstandard printers and/or inks. Thus, tags can be printed all over abook, magazine or other printed products. Alternatively or additionally,RF transponder tags as known in the art may be used. In someembodiments, the read information is deciphered by the reader. In otherembodiments, partially or completely unanalyzed information istransmitted to the computer for analysis.

Although an acoustic transmission of the tag information is preferred,RF transmission may also be practiced.

In the above description, a large number of permutations and possibleembodiments have been described. This type of description is utilizedfor the ease of describing the many different possible embodiments ofthe invention. It is appreciated by the inventors that some of thedescribed combinations may be known in the art. This is not to beconstrued as an admission of equivalence of the different embodimentsdescribed. Moreover, even such combinations which may be known may findpatentable utility from their application in particular situations.

The present invention has been described in terms of preferred,non-limiting embodiments thereof. It should be understood that featuresdescribed with respect to one embodiment may be used with otherembodiments and that not all embodiments of the invention have all ofthe features shown in a particular figure. In particular, the scope ofthe claimed invention is not limited by the preferred embodiments but bythe following claims. Section titles, where they appear, are not to beconstrued in limiting subject matter described therein, rather sectiontitles are meant only as an aid in browsing this specification. Whenused in the following claims, the terms “comprises”, “comprising”,“includes”, “including” or the like means “including but not limitedto”.

1. A method of communicating with an electronic device, comprising:providing an electronic device having an audible sound receiving andgenerating sub-system including a microphone; transmitting from a sourceat least one acoustic signal encoded with information; receiving said atleast one acoustic signal by said microphone; and determining at leastone of a spatial position, distance or movement of the microphonerelative to the source, responsive to the received at least one signal.2. A method according to claim 1, comprising transmitting to saidsource, using a loudspeaker associated with the electronic device, atleast a second acoustic signal, encoded with information, in responsewith said detected signal.
 3. A method according to claim 2, wherein atleast one of said at least one first signal and at least a second signalcomprise an ultrasonic signal.
 4. A method according to claim 1, whereinsaid electronic device comprises a computer.
 5. A method according toclaim 4, wherein said source comprises a computer peripheral.
 6. Amethod according to claim 5, wherein said peripheral comprises aprinter.
 7. A method according to claim 4, wherein said computercomprises a personal digital assistant (PDA) or a portable computer. 8.A method according to claim 1, comprising extracting said encodedinformation by the electronic device.
 9. A method according to claim 1,wherein determining a spatial position, distance or movement comprisesdetermining a distance between said microphone and said source.
 10. Amethod according to claim 1, wherein determining a spatial position,distance or movement comprises determining movement of said microphonerelative to said source.
 11. A method according to claim 9, wherein saidmovement comprises angular movement.
 12. A method according to claim 1,wherein determining at least one of a spatial position, distance ormovement comprises determining a spatial position of said microphonerelative to said source.
 13. A method according to claim 12, whereinsaid spatial position is a one-dimensional spatial position.
 14. Amethod according to claim 12, wherein said spatial position is atwo-dimensional spatial position.
 15. A method according to claim 12,wherein said spatial position is a three-dimensional spatial position.16. A method according to claim 1, wherein the source comprises apointing implement and comprising emulating a touch screen or pointingdevice behavior on a screen of the electronic device responsive to thereceived at least one acoustic signal.
 17. A method according to claim1, wherein said source comprises a toy.
 18. A method according to claim17, comprising controlling at least one action of the toy, responsive tosaid received at least one acoustic signal.
 19. A method according toclaim 1, wherein said information comprises music.
 20. A methodaccording to claim 1, wherein said information comprises personalinformation.
 21. A method according to claim 1, wherein said sourcecomprises a smart card.
 22. A method according to claim 1, wherein saidsource comprises a computer.
 23. A method according to claim 1,comprising logging into a computer system responsive to said received atleast one signal.
 24. A method according to claim 1, wherein saidacoustic signal comprises human audible sound.
 25. A method according toclaim 24, wherein said acoustic signal has a main frequency over 10 kHz.26. A method according to claim 1, wherein said acoustic signal has amain frequency which is infra-sonic.
 27. A method according to claim 1,wherein said information is encoded on the acoustic signal using belowhuman-threshold amplitudes.
 28. A method according to claim 1, whereinsaid information is encoded using below human-threshold amplitudevariations.
 29. A method according to claim 1, wherein said acousticsignal has a main frequency below 50 kHz.
 30. A method according toclaim 1, wherein said acoustic signal has a main frequency below 25 kHz.31. A method according to claim 1, comprising retransmitting saidacoustic signal to a remote computer which analyses said receivedacoustic signal to determine information encoded by said acousticsignal.
 32. A method of attaching a peripheral to a computer,comprising: providing a general purpose computer including a soundgenerating and receiving subsystem; analyzing, at said computer, soundsreceived by said subsystem to detect acoustic transmissions from saidperipheral; and transmitting, from said computer and using saidsubsystem, information to said peripheral using encoded soundtransmissions.
 33. A method according to claim 32, wherein said soundtransmissions are audible.
 34. A method of determining a status of anelectronic device, comprising: receiving information-encoding acousticsignals generated by said device; and analyzing said signals,automatically by a computer, to determine an operational statusassociated with said device responsive to said information.
 35. A methodaccording to claim 34, wherein said status comprises a status of saiddevice.
 36. A method according to claim 34, wherein said statuscomprises a status of a second device attached by computercommunications with said device.